All right here is the scenerio, I bought an 88 convertible for 700. The body is in great shape top and so on but the motor was gone. They had started to do a turbo swap but never finished. The car has the turbo hood, tranny wheels, driveshaft, and i believe the wiring harness cause when i look for any wiring diagrams i have to follow the turbo part. Now the comp im not sure if its a N/A or turbo the # on it is N326 18 881C.
By the way the car had a N/A engine in it with the oil injectors clogged and not working. Any light on this subject would seriously help me. Thanks

 

The N326 is a 86-87.5 Non-turbo ECU.

Normally that car would use the N338 ECU, and a Turbo would use a N332, N333 or N338 ECU.

 

I appreciate your info that could be the main reason that car wouldn't start, alot of the wiring is just all messed up, rewired, and one wire in each side of the engine bay is melted the length of the wire. What gets me is they have a wire going from the ecu to a relay two other wires grounded out and another going back around the ecu. The guy that had this before seemed like he had no idea how to really work on a car, but hey thanks again

 

You need to either get rid of it or pay someone who is competent to fix your electrical problems. Electrical problems is one of the hardest to troubleshoot and fix - that's why people pay big money to get this kinda work done. It's next to impossible to try and help you out efficiently by typing text over this forum.


-Ted

 

An NA ecu will start a turbo car, and a turbo ecu will start a NA car. unless the ecu is just plain bad, you have another problem, it should start and run fine with that ecu(as far as startup, idle, and **LIGHT** driving).

 

Wait a sec, so the N/A vert uses a turbo ECU?!?! I'm lost.

 

Apparently since all jspec 'verts were turbo, they thought better of using NA ecu's in them, and instead put in a version that would operate either an NA or turbo. I have been told this repeatedly but have never tried it personally (vert ecu on turbo car). The verts all have their own ecu's that are said to run any FC, period. You can use a NA FC coupe ecu in a vert so long as it retains the stock NA motor, though, it is the same thing.

 

The turbo and S4 vert ECUs are tuned for gas mileage, and emissions, rather than power. And since the 'vert everywhere else in the world but North America was sold as a Turbo, Mazda used a Turbo ECU and just swapped engine harnesses and engines depending on the market.

It was important for Mazda in 84-88 to meet the CAFE regulations on the S4 FC or there would have been a gas guzzler tax on them. That is why there is no offical auto tranny 88 'verts (according to the EPA). The extra 80 lbs of the Auto tranny and decreased gas mileage would have resulted in the 88 'vert being labled a gas guzzler.

The CAFE regulations relaxed in early 88 (for the 89+ model year cars) and with enough other Mazda cars surpassing the CAFE, so mazda could use credits from other cars, to make up for the RX-7s gas mileage short comings.

 

We got the info from the now defunct Donnie Peters from Sun Auto.
We've tried the N338 vert ECU in 1987/1988 Turbo II's, and it does indeed work...surprisingly.


-Ted

 

So that suggests that the fuel and timing maps for turbo and nonturbo ecu's are the same up to and including atmospheric, or am I missing something?

If that is the case, why the hell didnt they just make one ecu for s4, and one for s5, and be done with it. IT would have cut costs and confusion a lot, would it not? There has to be more to the story...

 

Are those the ECU's for turbo S4's?

 

332 and 333, yes. the 338 is an s4 vert ecu, which turns out to be just another s4 turbo ecu.

 

Hey thanks for all your replies, they do help me out but i got the car for only like 700 dollars the body, top, interior is in great shape along with the turbo wheels, hood tranny, driveshaft and rearend i don't think i could have gotten a better deal except with a running engine.
When i did a compression check the rear had almost perfect comp about 100psi. But the front was all over the place, bounced up to 90 then down to 60 up to 80 then down to 50. It got all weird. So i just figured ill get a jdm turbo find a comp and wiring and make a
conversion. Plus i have always heard the turbo's were a bunch farther. Oh yeah the other prob with the engine is none of the front oil injectors were not working could have been the cause of the failed front rotor. Thanks again guys

 

sorry i meant funner not farther, god i need a life

 

N332 is for the S4.

 

Yeah, we were wondering the same thing. We don't have the ***** to run an (strict) NA ECU on a Turbo II yet. The part number would give you a slight clue on the turbo potential (i.e. N33x), but I dunno how it's running maps for both turbo and NA in it. Maybe it's just a turbo ECU running on NA parameters - would explain the "slow" nature of the vert.

It looks like Henrik cracked the ECU coding, so maybe he might want to take a look at the N338 code maybe?


-Ted